Email Marketing Metrics Report

Bounce Rates

July 2011 Edition

Bounce rate represents the percentage of recipients who did not receive a given email message. When an email does not reach the recipient's inbox due to an invalid email address it is considered a bounce and is returned to the sender as "undeliverable".

An email campaign's bounce rate is an important metric to monitor and manage regularly. Abnormally high bounce rates will send a red flag to the Email Service Provider and is cause for investigation to ensure the email list contains valid and up-to-date email addresses.

Average Bounce Rate by Mailing Frequency

According to our findings, the more frequently email marketers sent emails last year the lower their bounce rates were.

The frequency with which email marketers send their campaigns can have a drastic effect on the campaign's overall bounce rate. According to our findings, clients that sent emails to their subscribers less than once a month (5.1%) had the highest bounce rate. Conversely, clients sending emails more frequently, such as once a day or more, saw the smallest bounce rate (0.4%).

Average Bounce Rate by Mailing Frequency

Average Bounce Rate by Industry

MailerMailer identified the average bounce rates across several industries. Based on our findings, the Large Business (2.5%), Wholesale (2.5%), Real-Estate (2.4%), and Consulting (2.4%) industries generated the highest volume of bounced emails. These industries often collect large volumes of email addresses through various online and offline methods increasing the potential for misspellings or purposely incorrect email addresses.

Industries that experienced the lowest bounce rates included Consumer and Transportation both at 0.7% and Banking, Entertainment, Media, Religious and Restaurant all with a 0.9% bounce rate. This suggests that these industries maintain well-targeted lists, provide relevant information and closely monitor their lists.

Note: MailerMailer customers select their industry upon signing up for the email service. The findings below are based on data provided by each customer.

Average Bounce Rate by Industry

Average Bounce Rate by Industry and List Size

Based on our findings, it appears that list size does not have an overwhelming effect on email bounce rates in the following three list sizes. Overall the bounce rate remains fairly consistent across each list size with an average bounce rate of 1.6% and 1.7% in list size containing 25-499 and 500-999 subscribers respectively and a bounce rate of 1.4% in lists sizes over 1,000.*

25-499 List Members

500-999 List Members

1000+ List Members

Average Bounce Rate by Industry and List Size

* This data was found by first extracting the industries with abnormally high bounce rates, including the Computer industry with a 17.1% bounce rate in lists ranging from 25-499 and Real Estate with a bounce rate of 14.7% in the 500-999 list size and calculating the average bounce rate for each list.

Average Bounce Rate by Number of Recipients

Although our data indicates that list size does not greatly affect bounce rates, the following graph offers a unique perspective on how the number of recipients may affect an email's bounce rate. Additionally, this graph provides a greater level of detail as it analyzes larger list sizes.

In general, the bounce rate follows a seemingly straight line at approximately 1.2% until it begins to decline at 5,000 recipients. The various dips and spikes present in this chart are not statistically relevant because they do not indicate a significant trend.

Based on this data, emails that were sent to larger number of recipients, specifically 5,000-8,500, had the lowest bounce rate.

Average Bounce Rate by Number of Recipients

Note: Data collected for the 'Average Bounce Rate by Number of Recipients' excludes messages with a bounce rate greater than 20%.